Scavenging Hypothesis: Lack of evidence for Dog Domestication on the Waste Dump

Christoph Jung, Daniela Pörtl

Abstract

In the debate on canine domestication researchers have identified a lot of valid information regarding the time, region, and ancestor of the dog. But researchers are still figuring out, why and how this process started. The scavenging hypothesis, first proposed 2001 by Ray and Lorna Coppinger, proclaims the first human waste dumps as the ecological niche for the self-domestication-process of dogs. Many scientists refer to that model, sometimes partly modified. The scavenging hypothesis is broadcasted by most public media as the commonly accepted model of dog’s domestication. Thus we have to deal with that popular model. Based on a broad multi-disciplinary approach like human evolution, archaeology, palaeogenetics, psychology and neurobiology, we will look for evidence. Investigating nine assumptions of the scavenging hypothesis we did not find any evidence. Dog’s domestication started thousands of years before the advent of food waste dumps. The scavenging hypothesis cannot explain why only wolves and never foxes nor jackals have been domesticated. Paleolithic people and ancient wolves were living together closely in the same ecological niche hunting the same prey with the same cooperative methods. It is likely that they met very often and knew each other very well. We have some hints, that ancient wolves and people treated each other with respect cooperatively. We have hints for an active cooperation from humans and dogs starting in the Upper Paleolithic period long before it would have even been possible scavenging human waste. We have hints for emotional bonds between ancient people and dogs. Emotional bonds would have been unlikely for an animal hanging around human settlements while scavenging carrion and feces, like the scavenging hypothesizes describe. Looking at recent dogs and humans we have evidence for strong unique similarities in the psychological and neurobiological structures eventually allowing interspecific bonding, communication and working. Interspecific cooperation decreased the level of the stress axis of both species in the Paleolithic period and even does so today what improves our social and cognitive abilities. We propose that dogs domestication could be understand as an active social process of both sides. Further investigations need a closely networked multidisciplinary approach.